Security Updates for Microsoft Office Web Apps (September 2021)

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from the Microsoft Security Updates API. The text
# itself is copyright (C) Microsoft Corporation.
#

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(153470);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/11/30");

  script_cve_id("CVE-2021-38655");
  script_xref(name:"MSKB", value:"5001999");
  script_xref(name:"MSKB", value:"5002009");
  script_xref(name:"MSFT", value:"MS21-5001999");
  script_xref(name:"MSFT", value:"MS21-5002009");
  script_xref(name:"IAVA", value:"2021-A-0425-S");

  script_name(english:"Security Updates for Microsoft Office Web Apps (September 2021)");

  script_set_attribute(attribute:"synopsis", value:
"The Microsoft Office Web Apps installation on the remote host is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The Microsoft Office Web Apps installation on the remote host is missing security updates. It is, therefore, affected
by a remote code execution vulnerability. An attacker can exploit this to bypass authentication and execute unauthorized
arbitrary commands.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://support.microsoft.com/en-us/topic/description-of-the-security-update-for-office-online-server-september-14-2021-kb5001999-2ec36572-723b-4aea-81fc-937535743b63
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?a9006418");
  # https://support.microsoft.com/en-us/topic/description-of-the-security-update-for-office-web-apps-server-2013-september-14-2021-kb5002009-d911ed48-afd4-48ad-affe-dc157c5ea43b
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?7777f350");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released the following security updates to address this issue:  
  -KB5001999
  -KB5002009");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:F/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-38655");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/09/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/09/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/09/17");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:office_web_apps");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:office_online_server");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Windows : Microsoft Bulletins");

  script_copyright(english:"This script is Copyright (C) 2021-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("office_installed.nasl", "microsoft_owa_installed.nbin", "microsoft_office_compatibility_pack_installed.nbin", "smb_hotfixes.nasl", "ms_bulletin_checks_possible.nasl");
  script_require_keys("SMB/MS_Bulletin_Checks/Possible");
  script_require_ports(139, 445, "Host/patch_management_checks");

  exit(0);
}

include('smb_func.inc');
include('smb_hotfixes.inc');
include('smb_hotfixes_fcheck.inc');
include('install_func.inc');

get_kb_item_or_exit('SMB/MS_Bulletin_Checks/Possible');

var path, vuln;

var bulletin = 'MS21-09';
var kbs = make_list('5001999', '5002009');

if (get_kb_item('Host/patch_management_checks'))
  hotfix_check_3rd_party(bulletin:bulletin, kbs:kbs, severity:SECURITY_WARNING);

get_kb_item_or_exit('SMB/Registry/Enumerated', exit_code:1);

var port = kb_smb_transport();

# Get installs of Office Web Apps
var owa_installs = get_installs(app_name:'Microsoft Office Web Apps');

if (!empty_or_null(owa_installs))
{
  var owa_install;
  foreach owa_install (owa_installs[1])
  {
    if (owa_install['Product'] == '2013')
    {
      var owa_2013_path = owa_install['path'];
      var owa_2013_sp = owa_install['SP'];
    }
    else if (owa_install['Product'] == '2016')
    {
      var oos_path = owa_install['path'];
      var oos_sp = owa_install['SP'];
    }
  }
}
vuln = FALSE;

####################################################################
# Office Web Apps 2013 SP1
####################################################################
if (owa_2013_path && (!isnull(owa_2013_sp) && owa_2013_sp == '1'))
{
  path = hotfix_append_path(path:owa_2013_path, value:'WordConversionService\\bin\\Converter');
  if (hotfix_check_fversion(file:'sword.dll', version:'15.0.5381.1000', min_version:'15.0.0.0', path:path, kb:'5002009', product:'Office Web Apps 2013') == HCF_OLDER)
    vuln = TRUE;
}

####################################################################
# Office Online Server
####################################################################
if (oos_path && (!isnull(oos_sp) && oos_sp == '0'))
{
  path = hotfix_append_path(path:oos_path, value:'WordConversionService\\bin\\Converter');
  if (hotfix_check_fversion(file:'sword.dll', version:'16.0.10378.20000', min_version:'16.0.10000.0', path:path, kb:'5001999', product:'Office Online Server') == HCF_OLDER)
    vuln = TRUE;
}

if (vuln)
{
  replace_kb_item(name:'SMB/Missing/'+bulletin, value:TRUE);
  hotfix_security_warning();
  hotfix_check_fversion_end();
  exit(0);
}
else
{
  hotfix_check_fversion_end();
  audit(AUDIT_HOST_NOT, 'affected');
}